7-Amino-4-hydroxy-3-[2-sulfo-4-(p-sulfophenylazo)phenylazo]-2-naphthalenesulfonic acid

3-[4-[(4-Sulfophenyl)azo]-2-sulfophenylazo]-4-hydroxy-7-amino-2-naphthalenesulfonic acid

7-amino-4-hydroxy-3-[[2-sulpho-4-[(4-sulphophenyl)azo]phenyl]azo]naphthalene-2-sulphonic acid